package Demo1;

public class Computer {
    public void open(){
        System.out.println("开机");
    }
    public void  close(){
        System.out.println("关机");
    }
    public void useUsbDevice(USB usb) {
        usb.openDevice();
        if (usb instanceof Mouse) {
            Mouse mouse = (Mouse) usb;
            mouse.click();
        } else {
            KeyBoard keyBoard = (KeyBoard) usb;
            keyBoard.input();
        }
        usb.closeDevice();
    }
}
